Each year, more than one billion travelers pass through U.S. airports, creating opportunities for respiratory viruses to spread rapidly across borders1 . To address this, the Centers for Disease Control and Prevention (CDC) has expanded its Traveler-based Genomic Surveillance (TGS) program to include influenza and respiratory syncytial virus (RSV), alongside SARS-CoV-2, enhancing early detection of respiratory pathogens at major U.S. airports2 . This expansion leverages nasal swab and wastewater sampling to monitor viral variants entering the country, providing critical data to inform public health responses3 .
The New Program Will Collect Nasal Swabs and Wastewater
The CDC’s expanded surveillance program operates at seven major U.S. airports, combining voluntary nasal swab collection and wastewater sampling to monitor respiratory viruses4 5. Nasal swabs are collected at six airports, excluding Boston Logan International Airport, where wastewater sampling is conducted exclusively4 5. At Boston, wastewater is gathered using a triturator device that collects samples from aircraft lavatories but not from terminal waste, enabling targeted pathogen detection from arriving flights4 5.
Four airports focus solely on voluntary nasal swab collection, while John F. Kennedy International Airport (JFK) and San Francisco International Airport (SFO) perform dual sampling of both wastewater and nasal swabs4 5. Travelers arriving at participating airports can anonymously and voluntarily self-collect two nasal swabs and complete a brief questionnaire, which helps provide context for detected viruses1 2. One swab is pooled with others for initial testing, and if positive, individual samples undergo further analysis including genomic sequencing to identify variants or mutations of public health importance1 .
Wastewater sampling is a passive method that does not require traveler participation. Samples are collected either from individual airplanes using custom collection devices during routine lavatory servicing or from airport triturators that consolidate wastewater from multiple aircraft1 6. These samples are tested using digital polymerase chain reaction (dPCR) or reverse transcription polymerase chain reaction (RT-PCR) to detect viral genetic material1 6. Positive samples undergo sequencing to characterize circulating strains or variants1 6.
This multimodal approach allows the CDC to monitor a broad spectrum of respiratory viruses, including influenza A and B, RSV, and SARS-CoV-2, providing a comprehensive picture of viral circulation among international travelers2 37.
- Seven U.S. airports participate in the program4 5.
- Nasal swabs collected at six airports; Boston collects only wastewater4 5.
- JFK and San Francisco airports conduct both nasal swabs and wastewater sampling4 5.
- Traveler participation in nasal swabbing is voluntary and anonymous1 2.
- Wastewater sampling is passive and does not require traveler involvement1 6.
“The expansion of the Traveler-based Genomic Surveillance program to flu, RSV, and other pathogens is essential as we head into fall respiratory season. The TGS program, which began during the COVID-19 pandemic, acted as an early warning system to detect new and rare variants of the SARS-CoV-2 virus and will do the same for other respiratory viruses going forward.”
— Dr. Cindy Friedman, Centers for Disease Control and Prevention2
What Are the Benefits of This Program?
The expanded TGS program offers several key benefits that enhance public health surveillance and preparedness. By monitoring respiratory viruses at international airports, the CDC can detect new and emerging viral strains before they spread widely within U.S. communities4 5. This early detection is critical for identifying resistant RSV and influenza variants, as well as novel SARS-CoV-2 strains, enabling timely public health interventions4 5.
The program’s voluntary nasal swab collection maintains traveler anonymity while gathering valuable genomic data. The accompanying brief questionnaire provides epidemiological context, improving understanding of virus transmission dynamics4 5. Wastewater sampling complements nasal swabs by capturing viral shedding from passengers onboard aircraft, offering a broader surveillance net without requiring individual participation4 5.
Early Warning System at Airports: The CDC’s airport surveillance program detected the SARS-CoV-2 variant BA.2.86 within days of its global identification, demonstrating the system’s ability to provide advance notice of emerging threats. This early warning capability helps public health officials prepare and respond before viruses spread widely. 23
Through these methods, the program fills gaps in global biosurveillance, especially in regions with limited testing capacity. It supports rapid identification of variants entering the U.S. from diverse international locations, enhancing the ability to forecast respiratory virus trends and inform vaccine development and immunization strategies1 38.
Additional benefits include:
- Early detection of respiratory virus variants entering the U.S. 45.
- Identification of resistant strains of RSV and influenza4 5.
- Anonymous and voluntary participation reduces barriers to sampling4 5.
- Wastewater sampling provides a non-invasive surveillance method4 5.
- Data supports public health decision-making and pandemic preparedness1 3.
“We have known that travelers are a very important population to consider for tracking new and emerging infections.”
— Dr. Cindy Friedman, Centers for Disease Control and Prevention3
Monitoring the Influx of Diseases and Staying Aware of Pandemic Threats
“The expansion of the Traveler-based Genomic Surveillance program to flu, RSV, and other pathogens is essential as we head into fall respiratory season.”
— Dr. Cindy Friedman, Centers for Disease Control and Prevention9
Surveillance systems like the TGS program play a crucial role in tracking infectious diseases and forecasting their spread, much like meteorological forecasting predicts weather patterns4 5. Early detection of respiratory viruses through traveler-based sampling helps public health officials respond proactively to reduce disease burden and prevent widespread outbreaks4 5.
Despite existing surveillance efforts, gaps remain in monitoring viral variants emerging outside the U.S. Testing travelers at airports addresses these gaps by providing timely data on new variants before they establish community transmission4 5. This enhanced surveillance improves forecasting of respiratory virus influxes and supports public health preparedness during peak respiratory seasons4 5.
💡 Did You Know? CDC's Traveler-based Genomic Surveillance program (TGS) collects nasal swabs and wastewater samples from arriving international travelers at select U.S. airports to detect communicable diseases early and monitor global viral trends1 .
Participation in nasal swab collection requires minimal effort and no cost for travelers, involving only a short survey and self-collected samples4 5. Wastewater surveillance operates passively, requiring no traveler involvement, yet offers valuable insights into circulating pathogens4 5. Together, these approaches provide straightforward, scalable surveillance to inform public health strategies4 5.
Key points about monitoring and preparedness include:
- Surveillance enables early detection and forecasting of outbreaks4 5.
- Traveler testing fills gaps in global variant monitoring4 5.
- Voluntary participation ensures ethical and practical sampling4 5.
- Wastewater sampling offers a non-invasive, passive surveillance tool4 5.
- Timely data supports public health responses and vaccination efforts4 5.
